As yet another spinoff of "The Wizard of Oz" arrives in theaters, it's almost hard to believe that the original film, which premiered 74 years ago, was, in many ways, a near disaster.

The 1939 classic took more than a dozen screenwriters, three directors, six soundstages, 23 weeks to shoot and cost nearly $3 million -- MGM's most expensive film that year. Though released to much fanfare, it lost money until 1956, when MGM leased it to CBS, which began showing it on television every year and turned it into a cultural phenomenon.

Even more surprising: Judy Garland, who played Dorothy and went on to become a huge star, was not the studio's first choice. And "Over the Rainbow," which became the film's iconic song, almost didn't make it in.

"There were problems all along, but mostly because this was uncharted ground," said Aljean Harmetz, author of "The Making of the Wizard of Oz," the definitive book on the film. "They were creating new techniques to do the special effects. They were creating characters that had never been on the screen before. They were doing fresh things. It was the early days of Technicolor, which had only been around three years."

For two of the three surviving diminutive actors who played Munchkins, it was one of the best experiences of their life.

"It was wonderful," Jerry Maren, the Munchkin in the middle who famously welcomes Dorothy to Munchkinland by handing her a lollipop, told ABCNews.com. Now 93, he even sang a few bars of the "Lollipop Song."

Maren, who was 16 at the time, said Garland was "an angel. She was so thoughtful and considerate. She was so nice to us. She was lovely to everybody."

"The reason that scene is so good is because we really did enjoy it," Ruth Robinson Duccini, now 95, told ABCNews.com. "That was a lot of fun. And that comes through in the scene."

"I know they can never make another movie like that," said Duccini, who played one of the Munchkin villagers when she was 20. "What amazes me is the interest in it. There's still so much interest in it. People love that movie."

"It has stood the test of time," said Harmetz, whose book will be released in a new edition this fall -- in time for the movie's 75th anniversary. "There were a number of compromises all the way through, and yet the compromises sometimes made the film better. I take it just as it is."

Before heading off to see the latest Wizard in "Oz The Great and Powerful," which opens today, keep reading to learn more about the original "Oz" and the film that almost wasn't.

The Book

After several failed careers, including actor and salesman, and declaring bankruptcy, author L. Frank Baum hit a goldmine when he published "The Wonderful Wizard of Oz" in 1900. The book became the bestselling children's book for two years and led to stage shows and a series of Oz books. MGM acquired the screen rights to the book in 1937.

The Screenplay

It would take more than a dozen screenwriters -- many of them uncredited, including the Cowardly Lion's Bert Lahr and poet Ogden Nash -- to come up with the finished screenplay for "Wizard of Oz." The first to have a crack at it, former newspaper reporter Herman Mankiewicz, knocked out a treatment in four days. Though he would win an Oscar for "Citizen Kane" a year later, his "Oz" was a mess. "It was a strange treatment -- all about Kansas -- and discarded immediately," Harmetz said.

The Directors

The film went through three directors. The first lasted a week and half before he was fired. Though he didn't direct the film, George Cukor did set the stage for Victor Fleming, who would helm most of the movie. Though Cukor told Harmetz that "this wasn't his type of thing," he did do costume tests for Garland, who had been fitted with a blonde wig and heavy makeup. "Cukor said, 'Take that blonde hair off her and scrub her face clean. This is a little girl.'"

Fleming followed that course and stayed on as director up until the Kansas sequences, when he got called over to replace, ironically enough, Cukor as director of "Gone with the Wind." King Vidor completed the filming of "Oz."

The Star

Garland was not MGM's first choice for Dorothy. Shirley Temple, then a big star, was. But she was under contract for a competing studio, which refused to loan her out. So MGM turned to their "little hunchback," the nickname the studio had given to Garland, whom they'd been grooming. At 16, she was believed to be too big and too old. Though she was already on a chicken-broth-only diet, the studio insisted she wear a corset and tied down her breasts to hide her figure, Harmetz said. Garland earned about $500 a week for the role, but it made her a huge star.

Oz

W.C. Fields was the first choice to play the Wizard, but Harmetz said, "the studio wouldn't meet his price." Instead, MGM turned to contract player Frank Morgan. "It would have been a much different wizard with W.C. Fields," she said. "I'm not sure you would have believed him as a frightened little man."

The Munchkins

To create Munchkin Land, MGM ended up hiring 124 little people. "They said give me every f***ing midget you can find," recalled Maren, the first to welcome Dorothy to Munchkinland. "They went and got em."

"I was 20 years old at the time, raised in a small town in Minnesota. I didn't even know there were other little people," said Duccini, who played a Munchkin villager. "That was the biggest thing for me -- was meeting all of these other little people."

These days, Duccini said, it's hard to watch the classic film "because everyone's going -- all my friends are no longer here."

Garland helped spread the rumors of wild Munchkin parties off the set, but Harmetz said they were part of a PR machine that made up most of the behind-the-scenes stories.

The Wicked Witch

Margaret Hamilton, who played the Wicked Witch of the West, nearly went up in flames. After delivering her line, "I'll get you my pretty, and your little dog, too," Hamilton was supposed to disappear into a hidden elevator below the stage just as flames shot up. But the flames erupted too soon, catching her hat and broom on fire. "Her face was terribly burned and she was out for six weeks," Harmetz said. "Luckily she was not replaced, but only because they didn't need her during those six weeks."

When she returned, her stunt double took over the fire scenes. But even the double spent a week in the hospital after she was blown off the witch's broomstick when it exploded.

The Tin Man

Buddy Ebsen, who later became famous as Jed Clampett in TV's "The Beverly Hillbillies," was originally cast as the Tin Man. But he developed a near-fatal reaction to the aluminum powder in his silver makeup. While Ebsen was hospitalized, actor Jack Haley was quickly hired to replace him.

"When Haley took over, they used an aluminum paste instead," Harmetz said. "But a little got in his eye, and he got an infection."

The Dog

Even Toto did not escape injury. Once, a wind machine blew the small Cairn Terrier across the floor. Another time, one of the Wicked Witch's guards accidentally stepped on the dog's paw and broke it. So Toto got a stand-in while her paw healed.

The star canine whose real name was Terry but was later changed to Toto because of the film's popularity earned $150 a week, less than his human co-stars but more than the little people who played Munchkins.

The Song

"Over The Rainbow," the movie's most iconic song, almost didn't make it in. Studio chief Louis B. Mayer nearly took it out because he believed "you can't have one of your actors singing in a barnyard," Harmetz said. But lyricist Yip Harburg lobbied heavily for it and was able to convince Mayer to leave it in.

The Film

When it came out, "Oz" was neither a commercial or critical success. The New Yorker said it had
"no trace of imagination, good taste or integrity" and the New Republic said it was full of "freak characters." Nonetheless, it was nominated for six Oscars, and won for best original score and best song for "Over the Rainbow."

Garland also received a special "juvenile" Oscar, to which she joked that she wasn't good enough for an "adult" award.